In the world of smartphones, bezels may be among the most hotly contested design features.

If you've followed any of the coverage of the latest devices, most notably Apple's new iPhone X, you likely have heard people talking about bezels. But you may not have known what they were or why they're important.

Here's a rundown on what bezels are and what all the debate is about:

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What is a bezel, and why is it such a big deal?

Hollis Johnson

Bezels are the borders between a screen and a phone's frame. Many of the latest smartphones have ultranarrow bezels, ones that almost seem to have disappeared.

Take a look at these different iPhone models. Note that the newest one — the iPhone X, which is in the middle — has the slimmest bezels of the three.

By narrowing the borders around a screen, manufacturers can devote more of the phone's front to its display, allowing them to offer a bigger screen in a smaller phone. The iPhone X, for example, has a larger screen that the iPhone 8 Plus, despite being a significantly smaller device.

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Samsung and Google kicked off the narrow bezel trend back in 2011.

Wikimedia Commons

The companies worked together to produce that year's Galaxy Nexus device, which featured narrow borders on the sides of its screen.

The device also was the first to feature virtual navigation buttons in place of physical ones, providing a glimpse of the future, where the size of phone screens wouldn't need to be constricted to allow room for buttons.

"Giant phones with big bezels feel really silly after using this phone," he wrote.

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But those in the pro-bezel camp are equally passionate.

Apple

Designers and technology enthusiasts feel strongly about bezels on both sides of the debate.

Those in favor of bezels argue that good design isn't about appearances alone; instead, usability is a necessary component. Plainly put, the borders around screens make phones easier to hold and use, they argue. Phones without them are an inherently flawed.

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The iPhone X was a big bone of contention between the opposite camps.

Hollis Johnson

Here's what representatives of the two sides had to say about the nearly borderless design of Apple's new smartphone:

Anti-bezel:

Wired's Steven Levy loved that the design allowed Apple to devote more room for the iPhone X's screen.

"The iPhone X is a big screen in a compact form factor," he wrote. He continued: "I found the display a noticeable, and greatly pleasurable, advance over my 'old' iPhone 7, whether watching 'The Big Sick,' streaming a live football game, or simply swiping through Instagram."

"Less ignorable are the bezels around the sides and bottom of the screen, which are actually quite large," he wrote.

Pro-bezel:

For Business Insider's Ben Gilbert, the phone's near-borderless design made the iPhone X uncomfortable to hold:

"With the iPhone X, the lack of a bezel not only means that I'm more likely to accidentally push something, but I also worry about dropping this phone. Instead of gripping the phone, I'm more likely to cradle it, so as not to hide the screen with any of my fingers."

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But the drive for bezel-less phones may not be a matter of design alone.

Antonio Villas-Boas/Business Insider

The push towards borderless screens and the rise of video technology are linked, said Gadi Amit, the founder at design studio New Deal Design. Phones aren't just phones anymore — they're our e-readers, television screens, and mini-computers.

"The carriers, phone manufacturers, and platforms such as Google and Apple all have a vested interest in providing more and more video," Amit said.

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So, what's the future of smartphone design?

Klemens Schillingen

Because of Apple's influence in the tech industry, bezels may be gone for good, predicted the Next Web's Napier Lopez.

"Manufacturers will race to shave off another millimeter here or there," he wrote. Lopez continued: "Eventually, someone will find a way to make the front camera and speaker array virtually undetectable, essentially turning our phones into one massive touchscreen."